Question: difference of stoch_simul in dynare 3 and 4

Hi dear all

I would like to ask a question that I got problems with dynare version 4:

I tried the same file to run the stoch_simul in both of the versions (3 and 4). why the results are different?
does anyone also have faced this situation?

Thank you for your help.

This should normally not happen. Please post an example.